Engine rotating speed extraction circuit applied to ANC circuit
By designing a directly connected speed conversion circuit module and voltage regulator unit, the problem of long engine speed signal transmission delay was solved, the noise reduction effect and real-time performance of the ANC system were improved, the cost was reduced, and the ANC controller was protected.
Patent Information
- Application Number
- CN202520173624.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-24
- Publication Date
- 2025-11-18
- Estimated Expiration
- 2035-01-24
AI Technical Summary
In existing technologies, there is a long delay in the transmission of engine speed signals from the engine to the ANC controller MCU, resulting in poor ANC noise reduction performance.
Design an engine speed extraction circuit, including a speed conversion circuit module, which is directly electrically connected to the engine and the ANC controller MCU. Through a primary voltage regulation and conversion unit and a secondary voltage regulation and protection unit, the engine speed signal is directly converted into a signal usable by the ANC controller MCU, reducing intermediate conversion steps and delays.
It improves the noise reduction effect of the ANC system, reduces signal delay, enhances the real-time performance and reliability of the signal, reduces costs, and protects the stability and lifespan of the ANC controller MCU.
Smart Images
Figure CN223562916U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of automobile, concretely relates to a engine speed extraction circuit for ANC circuit. BACKGROUND
[0002] ANC (Active Noise Cancellation, active noise cancellation) technology in the car through the built-in microphone real-time monitoring the noise in the vehicle, and using ANC control system sends the sound wave of opposite phase to cancel these noises, thereby significantly reducing the low-frequency noise level in the car, such as engine roar or road noise, provide more quiet and comfortable driving environment.This technology is particularly suitable for reducing those frequency range that traditional soundproofing materials are difficult to effectively handle, improve the overall driving experience and passenger comfort.
[0003] In the EOC (engine order noise reduction) application of reducing engine order noise, the extraction of engine speed is crucial.When the engine speed is extracted, the shorter the delay of the speed transmission to the main chip, the higher the efficiency, and theoretically the better the noise reduction effect of ANC algorithm.In the moment of speed extraction, the noise of the engine will be transmitted to the passenger compartment at the speed of sound, at this time, if the speed can be transmitted to the ANC (active noise cancellation) controller at a faster speed, the real-time performance of the calculated ANC counteracting sound wave is stronger, and the noise reduction effect is better.
[0004] In the prior art, the engine speed is transmitted to the ANC controller MCU using CAN bus, as shown in the figure, the engine speed is read through CAN, the real-time speed of the engine needs to be converted and analyzed through the ECU speed first, and then enter the CAN bus, and then enter the ANC (active noise cancellation) controller through the CAN transceiver, and then sent to the controller MCU after the CAN transceiver analyzes.The transmission is propagated at the speed of light, but each step of conversion requires a certain delay, and the higher the delay, the worse the noise reduction effect. Figure 1 UTILITY MODEL CONTENTS It is intended to provide a basic scheme, an engine speed extraction circuit for ANC circuit, to solve the technical problem of long time consumption of engine speed entering ANC controller.
[0005] An engine speed extraction circuit for ANC circuit, comprising: an input end for an automobile engine, for acquiring an engine speed signal; a speed conversion circuit module, one end electrically connected to the input end, the other end electrically connected to the output end, for converting the engine speed signal; an output end for an ANC controller MCU, for outputting the converted output signal of the engine speed to the MCU.
[0006]
[0007] The working principle and advantages of the basic scheme are as follows: different from the structure of the prior art, compared with the prior art, first, the basic scheme only provides a rotation speed conversion circuit module, one end is directly electrically connected with the automobile engine, and the other end is directly electrically connected with the ANC controller MCU, only the engine rotation speed signal needs to be converted once through the rotation speed conversion circuit module, and then the output signal required by the ANC controller MCU can be directly output, the intermediate transmission and conversion steps are greatly reduced, so that the ANC controller MCU can receive the engine rotation speed signal in real time, and the noise reduction effect of the ANC system is improved.
[0008] Secondly, the basic scheme provides a rotation speed conversion circuit module, only corresponding electronic components need to be provided, and a CAN receiver does not need to be arranged, so that the use cost is greatly reduced.
[0009] Further, the rotation speed conversion circuit module comprises: a primary voltage stabilization conversion unit, one end of which is electrically connected with the input end, and the other end is electrically connected with one end of a secondary voltage stabilization protection unit, for converting the engine rotation speed signal into a primary conversion signal; and the secondary voltage stabilization protection unit, the other end of which is electrically connected with the output end, for regulating the primary conversion signal as an output signal after voltage regulation.
[0010] Beneficial effects: by arranging the primary voltage stabilization conversion unit and the secondary voltage stabilization protection unit, the converted engine rotation speed signal can be stabilized twice. First, the primary voltage stabilization conversion unit converts the engine rotation speed signal into a primary conversion signal, so that the voltage and current reach a certain stable level, and the requirements of the input signal are preliminarily met. Then, the secondary voltage stabilization protection unit further regulates and protects the primary conversion signal, so as to ensure that the voltage of the output signal is stable and will not be too high, thereby protecting the ANC controller MCU from being affected by voltage fluctuation, and improving the stability and reliability of the entire circuit.
[0011] Further, the primary voltage stabilization conversion unit comprises a first resistor, a first triode, a first input power supply, a second resistor and a third resistor; one end of the first resistor is electrically connected with the input end, and the other end of the first resistor is electrically connected with a first port of the first triode; a third port of the first triode is electrically connected with one end of the second resistor, and the other end of the second resistor is electrically connected with the first input power supply; and a second port of the first triode is electrically connected with one end of the third resistor.
[0012] Beneficial effect: the first resistor limits the current of the input signal, preventing excessive current from damaging the subsequent circuit; the first transistor acts as a signal amplification element, amplifying the signal through the first resistor so that it can drive the subsequent circuit; the second resistor and the third resistor are used to set the working state of the transistor and the stability of the output signal. This combination design enables the primary voltage stabilization conversion unit to effectively convert and stabilize the engine speed signal, providing a reliable signal basis for the subsequent secondary voltage stabilization protection unit.
[0013] Further, the first port, the second port and the third port of the first transistor are the base, the emitter and the collector, respectively.
[0014] Beneficial effect: the base is used to receive the input signal, the emitter is used to output the signal, and the collector is used to amplify the current. This port configuration enables the transistor to work normally, realizing the functions of signal amplification and conversion, and ensuring the stable operation of the primary voltage stabilization conversion unit.
[0015] Further, the secondary voltage stabilization protection unit comprises a fourth resistor, a fifth resistor, a first capacitor, a second input power supply, a voltage stabilization diode and a second transistor; one end of the fourth resistor, the first capacitor and the voltage stabilization diode is electrically connected with the primary voltage stabilization conversion unit, and the other end of the fourth resistor, the first capacitor and the voltage stabilization diode is grounded; the first port of the second transistor is electrically connected with the primary voltage stabilization conversion unit, the second port of the second transistor is grounded, and the third port of the second transistor is electrically connected with the output end and one end of the fifth resistor, respectively; the other end of the fifth resistor is electrically connected with the second input power supply.
[0016] Beneficial effect: the fourth resistor, the fifth resistor and the first capacitor form a filter circuit, which can filter out noise and interference in the signal, making the signal more stable; the voltage stabilization diode is used to stabilize the voltage to prevent excessive voltage; the second transistor is used to further amplify and convert the signal. This design enables the secondary voltage stabilization protection unit to effectively regulate and protect the primary conversion signal, ensuring the stability and safety of the output signal, and providing a reliable signal input for the ANC controller MCU.
[0017] Further, the engine comprises a Hall sensor, and the input end is electrically connected with the Hall sensor for directly extracting the engine speed signal from the Hall sensor.
[0018] Beneficial effect: the Hall sensor can directly detect the speed of the engine and provide high-precision and high-reliability speed signal. By electrically connecting the input end with the Hall sensor, the engine speed signal can be directly obtained, reducing the intermediate links of signal transmission, reducing signal delay, improving the real-time and accuracy of the signal, and thus improving the noise reduction effect of the ANC system.
[0019] Further, the first resistor has a resistance of 150KΩ, which is used to limit the current of the engine speed signal.
[0020] Beneficial effect: the resistance of the resistor is large, and is connected to the input terminal, which is used to directly limit the current of the engine speed signal.
[0021] Further, the second input power supply is 5V.
[0022] Beneficial effect: setting the second input power supply to 5V meets the working voltage requirement of the secondary voltage stabilization protection unit circuit, can provide stable power voltage for the circuit, and ensures the normal operation of the circuit and the stable output of the signal.
[0023] Further, it further comprises a first circuit board, and a speed conversion circuit module is arranged on the first circuit board; the first circuit board is close to the ANC controller MCU.
[0024] Beneficial effect: the speed conversion circuit module is arranged on the first circuit board, and the first circuit board is close to the ANC controller MCU, which can reduce the distance and interference of signal transmission, improve the stability and real-time performance of the signal. At the same time, this layout is also conducive to the integration and maintenance of the circuit, making the entire engine speed extraction circuit applied to the ANC circuit more compact and efficient.
[0025] Beneficial effect of the present scheme
[0026] Firstly, the present scheme provides an engine speed extraction circuit applied to the ANC circuit, which skips the CAN analysis link, increases the conversion efficiency, reduces the speed delay, and improves the noise reduction effect of the ANC controller.
[0027] Secondly, the input terminal is used as a Hall sensor, and the speed signal is directly obtained from the Hall sensor, which has stronger real-time performance and higher reliability.
[0028] Then, compared with the prior art which needs to use a CAN transceiver, the present scheme only needs to use an engine speed extraction circuit applied to the ANC circuit arranged on the first circuit board, which has simple circuit components and low cost; and is close to the ANC controller and far away from the engine, is not easily disturbed by the heat and temperature transmitted outward by the engine during operation, has strong stability, high durability, high reliability, and low failure rate.
[0029] Finally, only through the primary voltage stabilization conversion unit and the secondary voltage stabilization protection unit, the voltage of the output signal received by the ANC controller MCU can be reduced, which further protects the ANC controller MCU, has high safety and strong protection, does not interfere with or damage the ANC controller MCU, prolongs the service life of the ANC controller, and reduces the replacement cost of the ANC controller. BRIEF DESCRIPTION OF DRAWINGS
[0030] Figure 1 This is a schematic diagram illustrating the transmission of engine speed from the CAN bus to the ANC controller MCU in the existing technology.
[0031] Figure 2 This is a schematic diagram illustrating the transmission of engine speed from the engine to the ANC controller MCU in this embodiment;
[0032] Figure 3 This is a schematic diagram of the circuit structure of an engine speed extraction circuit applied to an ANC circuit in this embodiment. Detailed Implementation
[0033] The following detailed explanation illustrates the specific implementation methods:
[0034] The markings in the accompanying drawings include:
[0035] Input signal RPM, output signal RPM-S, initial conversion signal M-RPM, first transistor Q1, second transistor Q2, first resistor R1, second resistor R2, third resistor R3, fourth resistor R4, fifth resistor R5, first capacitor C1, Zener diode D1, first input power supply U1, second input power supply U2, ground GND.
[0036] Example
[0037] like Figure 2 As shown, this embodiment provides an engine speed extraction circuit for an ANC circuit. The engine speed extraction circuit includes an input terminal, a speed conversion circuit module, and an output terminal. One end of the speed conversion circuit module is electrically connected to the input terminal, and the other end is electrically connected to the output terminal. The input terminal is a Hall sensor on the camshaft of the automotive engine, and the output terminal is the ANC controller MCU. The Hall voltage generated by the Hall sensor is converted into an electrical signal, which is used as the engine speed signal, i.e., the input signal RPM. After the input signal RPM is converted by the speed conversion circuit module, it is transformed into an output signal RPM-S, which is then provided to the ANC controller MCU in real time. In this embodiment, the speed conversion circuit module covers and is mounted on a first circuit board, which is close to the ANC controller MCU.
[0038] The rotation speed conversion circuit module comprises a primary voltage stabilization conversion unit and a secondary voltage stabilization protection unit. The primary voltage stabilization conversion unit comprises a first resistor R1, a first transistor Q1, a first input power supply U1, a second resistor R2 and a third resistor R3. The secondary voltage stabilization protection unit comprises a fourth resistor R4, a fifth resistor R5, a first capacitor C1, a second input power supply U2, a voltage stabilization diode D1 and a second transistor Q2. One end of the primary voltage stabilization conversion unit is electrically connected to the input end, and the other end is electrically connected to one end of the secondary voltage stabilization protection unit. The other end of the secondary voltage stabilization protection unit is electrically connected to the output end. After the input signal RPM passes through the primary voltage stabilization conversion unit, the primary conversion signal M-RPM is output. At this time, the primary conversion signal M-RPM can already drive the IO port of the MCU, but the voltage of the primary conversion signal M-RPM is too large, which is easy to damage the ANC controller MCU. The primary conversion signal M-RPM is regulated by the secondary voltage stabilization protection unit to output the output signal RPM-S to the output end.
[0039] Specifically, as shown in the figure, Figure 3 The input end of the engine rotation speed extraction circuit is electrically connected to a Hall sensor connected to the automobile engine. The Hall voltage generated by the Hall sensor is converted into an electrical signal, which is used as the input signal RPM of the engine rotation speed extraction circuit. The input end is electrically connected to the left end of the first resistor R1. The right end of the first resistor R1 is electrically connected to the first port of the first transistor Q1. The third port of the first transistor Q1 is electrically connected to the lower end of the second resistor R2. The upper end of the second resistor R2 is electrically connected to the first input power supply. The second port of the first transistor Q1 is electrically connected to the left end of the third resistor R3. The first port of the first transistor Q1 is the base, the second port is the emitter, and the third port is the collector. The voltage of the first input power supply is 5V. The first resistor R1 is 150KΩ. The second resistor R2 is 4.7KΩ. The third resistor R3 is 10KΩ.
[0040] The right end of the third resistor R3 is electrically connected with the upper end of the fourth resistor R4, and the lower end of the fourth resistor R4 is grounded GND. The right end of the third resistor R3 is electrically connected with the upper end of the first capacitor C1, and the lower end of the first capacitor C1 is grounded GND. The right end of the third resistor R3 is electrically connected with the upper end of the stabilizing diode D1, and the lower end of the stabilizing diode D1 is grounded GND. The upper end of the stabilizing diode D1 is an input end, and the lower end of the stabilizing diode D1 is an output end. The fourth resistor R4 is 100KΩ, and the first capacitor C1 is 220pF. The right end of the third resistor R3 is electrically connected with the first port of the second triode Q2, the second port of the second triode Q2 is grounded, the third port of the second triode Q2 is electrically connected with the lower end of the fifth resistor R5, and the upper end of the fifth resistor R5 is electrically connected with the second input power supply. The third port of the second triode Q2 is electrically connected with the output end. The first port of the second triode Q2 is a base, the second port is an emitter, and the third port is a collector. The fifth resistor R5 is 10KΩ, and the second input power supply is 5V. The output end is a controller MCU, and the controller MCU is an MCU of an ANC active controller.
[0041] The Q1 triode is used for amplifying the signal through the first resistor R1; the stabilizing diode D1 is used for stabilizing voltage to prevent the input signal from damaging the engine speed extraction circuit.
[0042] Implementation principle of the embodiment
[0043] The input end of the engine speed extraction circuit is electrically connected with the Hall sensor connected with the automobile engine. It is known that the Hall sensor and the automobile engine are in synchronous shaft motion state. When the crankshaft of the automobile engine rotates, the magnetic components on the crankshaft interact with the permanent magnet in the Hall sensor, a changing magnetic field is generated, and then a Hall voltage is generated in the Hall sensor and converted into an electrical signal output. The electrical signal output can be used as the input signal of the engine speed extraction circuit. At the same time, the Hall sensor detects the speed by using the change of the magnetic field, so that the electrical signal has high precision and reliability.
[0044] The Hall voltage generated in the Hall sensor is converted into an electrical signal output. The converted electrical signal is similar to a PWM pulse wave, which has the characteristics of large amplitude, small current and poor driving ability, and cannot be directly transmitted to the MCU for analysis. Through practical detection, the amplitude of the wave is 12Vpp, and the current is 0.08mA. The converted signal is the input signal of the engine speed extraction circuit.
[0045] Because the current of the converted electric signal is very small, by selecting the first resistor R1 of 150KΩ, the resistor with large resistance value limits the current of the whole engine speed extraction circuit, preventing the current value of the input signal from being too large to cause abnormal work of the Hall sensor. Then the signal passing through the first resistor R1 is amplified through the first transistor Q1, and the initial conversion signal M-RPM signal is obtained after passing through the third resistor R3. At this time, the initial conversion signal M-RPM signal can already drive the IO port of the MCU, and the IO port of the MCU is the output end of the engine speed extraction circuit, but at this time the voltage is too large and may damage the MCU, then the second transistor Q2 and the stabilizing diode D1 are used to perform secondary voltage stabilization, voltage limiting and signal inversion on the initial conversion signal M-RPM signal to obtain a usable speed signal, and the speed signal is output as an output signal and output to the IO port of the MCU. In addition, because the duty cycle of the PWM wave is 50 to 50, even if it is flipped, it will not affect the calculation of the speed, and finally a usable output signal RPM-SW is obtained, which is input to the controller MCU for PWM analysis.
[0046] In the description of the utility model, it needs to be explained that the terms "upper", "lower", "left", "right" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly used when the utility model product is used, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation on the utility model.
[0047] In the description of the utility model, it also needs to be explained that, unless otherwise specified and limited, the terms "set", "install", "connect", "connect" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or it can be indirectly connected through an intermediate medium, it can be the communication between two elements. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.
[0048] It should be understood that the term "and / or" used herein is only to describe the same field of associated objects, which means that there can be three kinds of relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects have an "or" relationship.
[0049] Although the subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.
[0050] The above is only the embodiment of the present application, and the common knowledge of specific structures and properties in the scheme is not described in detail, the ordinary skilled in the art knows all the ordinary technical knowledge in the technical field of the present application before the application date or the priority date, can know all the prior art in the field, and has the ability to apply the conventional experimental means before the date, the ordinary skilled in the art can improve and implement the present scheme under the inspiration given in the present application, some typical known structures or known methods should not become the obstacle for the ordinary skilled in the art to implement the present application. It should be pointed out that for those skilled in the art, without departing from the structure of the present application, a number of modifications and improvements can be made, which should also be considered as the protection scope of the present application, which will not affect the effect and practicality of the present application. The protection scope of the present application should be subject to the content of its claims, and the specific implementation mode and the like in the specification can be used to explain the content of the claims.
Claims
1. An engine speed extraction circuit for application to an ANC circuit, characterized by, The application relates to an engine speed conversion circuit module. The input end is connected with an automobile engine for obtaining an engine speed signal. The speed conversion circuit module is electrically connected with the input end at one end and the output end at the other end, and is used for converting the engine speed signal. The output end is an ANC controller MCU, which is used for outputting the converted engine speed signal to the MCU.
2. An engine speed extraction circuit for use in an ANC circuit according to claim 1, characterized in that The speed conversion circuit module comprises: A primary voltage stabilization conversion unit, which is electrically connected with the input end at one end and the secondary voltage stabilization protection unit at the other end, and is used for converting the engine speed signal into a primary conversion signal. The secondary voltage stabilization protection unit is electrically connected with the output end at the other end, and is used for outputting the primary conversion signal as an output signal after voltage regulation.
3. An engine speed extraction circuit for use in an ANC circuit according to claim 2, characterized in that The primary voltage stabilization conversion unit comprises a first resistor, a first triode, a first input power supply, a second resistor and a third resistor. One end of the first resistor is electrically connected with the input end, and the other end of the first resistor is electrically connected with the first port of the first triode. The third port of the first triode is electrically connected with one end of the second resistor, and the other end of the second resistor is electrically connected with the first input power supply; and the second port of the first triode is electrically connected with one end of the third resistor.
4. An engine speed extraction circuit for use in an ANC circuit according to claim 3, characterized in that The first port, the second port and the third port of the first triode are respectively a base, an emitter and a collector.
5. The engine speed extraction circuit for use in an ANC circuit according to claim 2, characterized by The secondary voltage stabilization protection unit comprises a fourth resistor, a fifth resistor, a first capacitor, a second input power supply, a voltage stabilization diode and a second triode. One end of the fourth resistor, the first capacitor and the voltage stabilization diode is electrically connected with the primary voltage stabilization conversion unit, and the other end of the fourth resistor, the first capacitor and the voltage stabilization diode is grounded. The first port of the second triode is electrically connected with the primary voltage stabilization conversion unit, the second port of the second triode is grounded, and the third port of the second triode is electrically connected with the output end and one end of the fifth resistor; the other end of the fifth resistor is electrically connected with the second input power supply.
6. An engine speed extraction circuit for use in an ANC circuit as claimed in any one of claims 1 to 5, wherein The engine comprises a Hall sensor, and the input end is electrically connected with the Hall sensor for directly extracting the engine speed signal from the Hall sensor.
7. The engine speed extraction circuit for use in an ANC circuit according to claim 3, characterized by The resistance value of the first resistor is 150K omega, which is used for limiting the current of the engine speed signal.
8. The engine speed extraction circuit for use in an ANC circuit according to claim 5, characterized by The second input power supply is 5V.
9. The engine speed extraction circuit for use in an ANC circuit according to claim 1, characterized by, The application further comprises a first circuit board, the speed conversion circuit module is arranged on the first circuit board, and the first circuit board is close to the ANC controller MCU.